Dental tooth-drilling tool.



W. E. CHESTER.

DENTAL TOOTH DRILLING TOOL. APPLICKTIONYFILED JULY 10,1916.

Patented Oct. 10, 1916.

QTTOP/VFY u WILLIAM E. CHESTER, OF NORWOOD, OHIO.

DENTAL TOOTH-DRILLING TOOL.

Specification of Letters Patent.

Patented Oct. 10, 1916.

Application filed July 10, 1916. Serial No. 108,509.

To all whom it may concern:

Be itknown that I, WILLIAM E. CHESTER, a citizen of the United States of America, and a resident of Norwood, in the county of Hamilton and State of Ohio, have invented certain new and useful Improvements in Dental Tooth-Drilling Tools, of which the following is a specification.

This invention relates to dental toothdrilling tools and, more particularly, to drills used in preparing the cavities for the upright posts or pins that are set in the tops of tooth-roots for supporting artificial crowns thereon.

The details referring to the objects and parts of the structure herein will be fully hereinafter described in connection with the accompanying sheet of drawings, in which latter Figure 1 is an elevation, partly in section, of the peculiar form of tool used in connection with the post-cavity of a tooth-root, in the upper part of which cavity a boxing is intended to be used, a vertical section of a tooth-root being shown projected axiallybelow said tool in this view and showing the result of an operation by the tool in forming the post and box cavities therein; Fig. 2, an end view of the active or cutting end of the tool shown in Fig. 1; Fig. 3, an elevation of a similar form of tool to that shown in Fig. 1 but intended for use only in connec-' tion with a cavity in a tooth-root that is not supplied with a post-boxing, a tooth-root being also shown in this view projected axially below the tool and showing the result of an action by said tool ready for a post to be used without any boxing in the root; and Fig. 4, an end view of the active or cutting endof the tool shown in Fig. 8.

The tool is composed of an attachingshank 1 having a flange or collar 2 at its lower end, such flange 2 being circularly grooved or recessed at 3 in its lower face so as to provide for a peripheral, toothed or serrated edge 4 disposed downwardly; a circular-extension 5 having a lower, peripheral, toothed or serrated cutting-edge 6, also disposed downwardly; and a tapered serrated point 7 extending axially from said circularextension 5. This tool, of the specific form seen in Fig. 1, is adapted to perform service in forming a cavity in the top of a toothroot, such as that shown in Fig. 1, the tool itself being also shown in that view. The peculiar form of cavity provided in said lts bottom at its extreme diameter.

tooth-root in Fig. 1 is composed of the usual pulp-canal 9 that has at its upper end a shoulder 10, an expanded-chamber 11, and a still further expanded-chamber 12, the latter; being at the top or summit of the root. The largest chamber 12 at the top of the root is provided with a circular-groove 13 in The two expanded-chambers and the shoulders formed in the top of the pulp-canal of the tooth-root constitute the cavity in which a centrally-orificed boxing or bushing is used for the support of a vertical pin or post, such as is used in tooth roots for supporting crowns, said boxing or bushing being intended to duly reinforce the upper part of the root structure and to form a firm foundation for the crown-supporting post, and neither boxing nor post being shown herein because such details or parts may be of varied structures. In forming the shoulders and enlarged chambers in the upper part of the tooth-root, or rather of its pulp-canal,

the lower serrated-edge 6 of the part 5 of the tool is employed to cut the lower shoulder and to ream out the tooth substance for the lesser diameter in the top of the pulp-canal immediately following. the advance cutting or drilling of the point 7 into the upper end of said pulp-canal; and then the chamber of largest diameter at the top of the root is reamed out by the serrated-edge 4 and the toothed or serrated bottom 3 of the circulargroove that is made in the lower face of the flange 2 of the tool, such face 3 of that tool being best shown in the end view, Fig. 2. The tool, however, that is serrated cuttingadapted to prepare the upper part of the root-cavity for the use of a crown-supporting post, without a boxing or bushing in the upper part of the pulp-canal, is shown in Figs. 3 and 4, and such tool has an attaching-shank 14 that surmounts a flange-portion 15 whose lower peripheral-edge is toothed or serrated at 16 and has an axialextension 17, the latter being provided with a lower pointed-end 18 that is suitably toothed or serrated for drilling purposes into the upper end of the pulp-canal for the lower end of the upright post that is to be used in the top of the root and extends up wardly beyond the plane of the root for supporting the crown. The toothed 0r serrated edge 16 of this tool is adapted to ream out or cut the shouldered-portion 19 in the top of the pulp-canal 20 of the t th-ro t seen in Fig. 3, such shouldered-portion being in tended for the seating of a flange or collar, or otherwise enlarged part of the upright post used in the root for firmly supporting the crown. It is obvious, though, that the upper part of the 'root oavity can be prepared with the form of tool shown in Figs.

3 and 4 for use with a suitable boX therein,

= claim Y A dental tooth-drilling tool comprising an attaching-shank, a circular, solid-flange proif desired and necessary.

Copies of this patent may be obtained tor yided integrally at one end of said shank nained axial-extension.

WILLIAM E. CHESTER.

fivecentseach, by addressing the Commissioner of Patents, 7 Washington, D. Q. 

